Discovery of Potent and Selective Inhibitors of Toxoplasma gondii Thymidylate Synthase for Opportunistic Infections

作者：Zaware Nilesh; Sharma Hitesh; Yang Jie; Devambatla Ravi Kumar Vyas; Queener Sherry F; Anderson Karen S^*; Gangjee Aleem

来源：ACS Medicinal Chemistry Letters, 2013, 4(12): 1148-1151.

DOI：10.1021/ml400208v

• Opportunistic infection
• Toxoplasma gondii
• crystal structure
• thymidylate-synthase inhibitors
• active-site inhibitors

Infection by the parasite Toxoplasma gondii (tg) can lead to toxoplasmosis in iimnunocompromised patients such as organ transplant, cancer, and HIV/AIDS patients. The bifunctional thymidylate synthase-dihydrofolate reductase (TS-DHFR) enzyme is crucial for nucleotide synthesis in T. gondii and represents a potential target to combat T. gondii infection. While species selectivity with drugs has been attained for DHFR, TS is much more conserved across species, and specificity is significantly more challenging. We discovered novel substituted-9H-pyrimido[4,5-b]indoles 1-3 with single-digit nanomolar K-i for tgTS, two of which, 2 and 3, are 28- and 122 fold selective over human TS (hTS). The synthesis of these compounds, and their structures in complex with tgTS-DHFR are presented along with binding measurements and cell culture data These results show, for the very first time, that, in spite of the high degree of conservation of active site residues between hTS and the parasite TS, specificity has been accomplished via novel structures and provides a new target (TS) for selective drug development against parasitic infections.

• 出版日期2013-12